Or that they read RS422 on the Hyperdeck spec and listed it as a controllable device!

Who knows? It *might* work, but I wouldn't spend out without testing it first. If they tested it pre NAB then it was probably tested on the original firmware - IIRC this supported the basic play / stop / jog / shuttle commands but not jump to timecode.

What are you actually wanting to use it for? You can find RS422 deck controllers on ebay for peanuts - the protocol has been the same since Beta SP (or before even?) so any old controller *should* work if / when BMD sort out the issues with the protocol support on the Hyperdeck.